Abrading tool



July 14,A 1936. I J, W CQURTER I 21347256 ABRADING TOOL Filed July 7, 1955 Y Patented July 14, 1936 UNITED STATES PMENT orgies ABRADING TOOL Application `luly 7, 1933, Serial No. 679,402

3 Claims.

' This invention relates to abrading tools and is herein disclosed as embodied in a well-known type o f tool used extensively for buing the bottoms and particularly the shank portions of shoes, and l ordinarily referred to as a Naumkeag or rotary disk tool. Such a tool consists of a shank for attachment to a rotary spindle, and a disk-shaped portion which carries an abrasive cover. The diskshaped portion of the tool is frequently, although not always, padded; and in the case of a padded tool the pad may consist of a solid resilient material such as felt, or it may be of rubber inflated with air. In all cases where the marginal portion of the cover is secured to the rear face of the tool, however, it is important, in order to insure against A wrinkling or creasing oi the abrasive cover during the operation of the tool, to provide not only for securing the abrasive cover firmly in position but also for imparting some degree of tension to the cover. It is a common practice to apply the abrasive cover by means of a device designed particularly to draw the abrasive cover smoothly over the working face `of the tool body.

An object Vof the invention is to provide an improved arrangement for securing an abrasive cover under tension upon a rotary tool body without requiring any cover-applying device separate from the tool.

In the illustrated construction, the tool body is of the disk type and has a shank for attachment to a spindle, the means for tensioning the abrasive cover being adapted to engage the marginal portion of the abrasive cover and being forced into the cover-tensioning position by, for example, a nut threaded on the shank. In the illustrated tool, the cover-tensioning member consists of a sleeve having a plurality of prongs for engagement with the marginal portion oi the abrasive cover. Cooperating with these prongs is 40 a circular flange concentric with the spindle and extending rearwardly from the rear face of the disk, the prongs being arranged to engage tabs which extend from the margin of the abrasive cover over the circular flange so that when the 45 pronged member is moved toward the rear face of the disk it will pull the ends of the tabs with it and thereby tension the abrasive cover over the working face of the disk.

These and other features of the invention, including certain details of construction and Vcombinations of parts, will be more fully explained in the foregoing description, to be read in connection with the accompanying drawing, in 55 WhCh Fig. 1 is a perspective View of the improved buiing tool; Y

Fig. 2 is a View in longitudinal section of the tool; and n Fig. 3 is a View in perspective of a portion of the 5 tool.

The body portion of the tool shown in the drawing has a shank l Fi constructed and arranged for attachment to a rotary spindle l2. The spindle l2 has a shoulder lll beyond which extends a porl0 tion I6 of reduced diameter having threads it formed upon its end. This particular type of spindle has been selected for purposes of illustration because it is in common use in machines for performing edge-trimming operations upon l5 shoes and it is convenient, when the illustrated tool is to be used for bufiing shoe bottoms and shanks, to apply it to an edge-trimming machine. The shank it is tubular, its interior being formed to t over the spindle l2. Internal 20 threads 20 are formed in the shank l@ for cooperating with the threads i8 or" the spindle i2. The shank l0 has an internal shoulder which cooperates with the shoulder M of the spindle l2 to hold the shank in place when it is screwed 25 tightly on the end of the spindle I2. The threads I8 are so arranged, in relation to the direction of rotation of the tool, as to cause the tool to be tightened rather than loosened on the spindle it by the frictional drag of the work. Extending from the shank it is a iiange or disk 22 upon the outer face of which is secured a diskshaped pad 253, upon the outer or working face of which is mounted an abrasive cover 26. The pad 2t of the illustrated tool is composed of felt and is of greater diameter than the disk 22. The thickness of the pad 2li is sufficiently great to bring its working face beyond the end of the shank li) and also beyond the end of the spindle l2 so that there will be no danger of the central portion of the abrasive cover 26 40 bearing against these rigid members. Extending rearwardly from the rear face of the disk 22 is a circular flange 28 which is concentric with the shank lil. The flanges 28 and 22 taken together thus constitute a cup-shaped member. The abrasive cover 26 is generally circular in form and substantially coextensive with the Working face of the felt pad 24, except for the fact that the abrasive cover has three tabs 3i) extending from its margin rearwardly around the periphery of the pad 24 and over the rim of the cup-like structure formed by the flange 28. Slidably mounted upon the shank IB is a sleeve 32 having three arms 34 extending toward the rear face of the disk 22. Adjacent to the end of each of the arms 34 is a 55 shoulder 38, from which shoulder extends a point or prong 36. These prongs 36 serve to engage the ends of the tabs 30 which are turned over the flange 28. The shoulders 38 are considerably greater in area than the bases of the prongs 36, the purpose of the shoulders being to limit the extent of penetration of the tabs 30. The free ends of the arms 34 bear against the interior of the flange 28, but the arms are sufficiently resilient to yield to accommodate the thickness of the tabs 36. Formed in the interior wall of the flange 28 and registering with each of the prongs 3B is a groove 40. The prongs 36 thus travel in the grooves 4Q, respectively. The grooves 40, as shown in Fig. 2, are extended to form recesses in the face of the desk 22 to accommodate the prongs 36, in order to avoid blunting the points of the prongs when the sleeve 32 is forced down to its limiting position. Formed in the interior of the sleeve 32 is a slot 42 which engages a pair of pins 43 extending from the shank ill to position the sleeve 32 so that the prongs 36 will register with the slots 46, respectively. The exterior of the shank I0 is provided with threads 44 which are engaged by nut 46.

When it is desired to replace the abrasive cover 26 upon the tool body, the nut 46 is unscrewed to the left as viewed in Figs. l and 2 and the sleeve 32 is then manually pushed to the left, releasing the prongs 36 from the tabs 30 and enabling the abrasive cover to be removed. A new abrasive cover is now applied to the working face of the tool and its tabs 30 are turned over the edge of the flange 28. Holding the abrasive cover in this position, the operator screws the nut 46 toward the right, thereby pushing the sleeve 32 also toward the right and causing the prongs 36 to engage the tabs 39. Continued rotation of the nut 46 brings the arms 34 down into the cup-like construction and causes the shouldered and pronged ends of the arms to draw with them the turnedover ends of the tabs 3i), thus tensioning the abrasive cover tightly over the working face of the pad 24.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. An abrading tool comprising a rotary tool body having a disk shaped portion for supporting an abrasive cover and having a shank adapted for attachment to a rotary spindle, a member mounted for axial movement on said shank and having a plurality of pro-ngs for engagement with the marginal portion of an abrasive cover on said disk-shaped portion, and a nut threaded on said shank in abutting engagement with said pronged member for moving said pronged member axially on said shank toward said disk-shaped portion to tension the abrasive cover over said disk-shaped portion, said disk-shaped portion being constructed and arranged to cooperate with said prongs to tension the abrasive cover.

2. An abrading tool comprising a rotary tool body having a disk adapted on its working face to support an abrasive cover and having a shank adapted for attachment to a rotary spindle, a circular ange concentric with said spindle and extending rearwardly from the rear face of said disk, a plurality of prongs engageable with the marginal portion of an abrasive cover supported by the working face of said disk and turned over said ange, said prongs being constructed and arranged to press the marginal portion of the abrasive cover against the interior of said flange, and means for moving said prongs axially to pull the marginal portion of the abrasive cover into the space within said ange and toward the rear face of said disk, thereby tensioning said abrasive cover around said flange.

3. An abrading tool comprising a rotary tool body having a disk for supporting an abrasive cover and having a shank for attachment to a rotary spindle, an abrasive cover for the working face of said disk, a circular flange concentric with said shank and extending rearwardly from the rear face of said disk, said abrasive cover having tabs extending from its periphery over said flange, a member having a plurality of prongs for engaging said tabs respectively within said ilange, said member being movable axially on said shank toward said disk to cause said prongs to pull the tabs and thereby to tension the abrasive cover, and means for securing said pronged member in cover-tensioning position.

JOHN W. COURTER. 

